---
- name: test command output
  hosts: all
  tasks:
    - name: Test for VG existance
      command: vgs
      register: vgout
      ignore_errors: True

    - name: Show variable value
      debug: 
        var: vgout

    - name: print 
      debug: 
        msg: vg does not exist
      when: "'No such' in vgout.msg"